This invention relates to a device that secures a first housing to a second housing. In particular, the present invention relates to a unitary sheet metal clip that self-tightens on a retained housing when the retained housing is displaced.
The present invention provides a clip having a planar member and at least one retention member attached to the planar member. The planar member includes an inner perimeter, an outer perimeter, and defines a central axis. The least one retention member including a planar leg portion and a planar hook portion. The arrangement of the leg portion and the hook portion of the retention member create the self-tightening feature of the inventive clip.
The leg portion extends from the inner perimeter in a first direction along the central axis. The hook portion projects from the leg portion toward the central axis in a second direction, which is opposite the first direction along the central axis. The hook portion is acute to the central axis and has a free end located on an imaginary perimeter concentric to the inner perimeter of the planar member. The central axis and a plane passing through the hook portion of the at least one retention member form an angle in the range of approximately 20xc2x0-30xc2x0. Preferably, the angle comprises approximately 24xc2x0.
In a preferred embodiment of the invention, the planar member comprises an annulus, the imaginary perimeter comprises a circle, and the at least one retention member comprises a plurality of retention members. Particularly, five retention members uniformly disposed about the inner perimeter of the planar annulus.
The preferred embodiment further comprises a plurality of stiffeners. At least one of the plurality of stiffeners is disposed on the inner perimeter between two of the plurality of retention members. Each of the plurality of stiffeners comprises a lip extending in the engaging direction.
The present invention also provides a sheet metal clip for securing a first generally cylindrical housing member to a second generally cylindrical housing. The clip comprises a planar annulus, a plurality of retention members, and a plurality of stiffeners.
The planar annulus includes an inner perimeter, an outer perimeter, and defines a central axis. The plurality of retention members are uniformly disposed about the inner perimeter of the planar annulus. The plurality of stiffeners are arranged so that at least one of the plurality of stiffeners is disposed on the inner perimeter between two adjacent retention members of the plurality of retention members.
Each of the plurality of retention members includes a leg portion, a hook portion, and an arcuate portion disposed between the leg portion and the hook portion. The leg portion extends in an engaging direction and is substantially parallel to the central axis. The hook portion projects from the leg portion so that the central axis and a plane that passes through the hook portion form an angle in the range of approximately 20xc2x0-30xc2x0. The hook portion has a free end positioned on an imaginary circle concentric to the inner perimeter of the planar annulus.
The present invention also provides a method of retaining a first generally cylindrical housing to a second generally cylindrical housing while allowing for relative rotation between the cylindrical housings. The method comprises: (1) providing a sheet metal clip having an annulus and a plurality of retention members, each of the plurality of retention members including a leg portion and a hook portion, the leg portion extending from an inner perimeter of the annulus, the hook portion projecting from the leg portion toward a central axis of the annulus, the hook portion being acute to the central axis; (2) positioning the annulus of the clip within a retaining portion of the first housing member; and (3) locating the first housing member proximate the second housing member so that a free end of the hook portion of each of the retention members engages a protrusion on the second housing.
The present invention further provides a method of stamping a clip, which retains a first generally cylindrical housing to a second generally cylindrical housing. The method of stamping comprises: (1) punching a sheet metal circular configuration, the circular configuration having an interior cutout so that a plurality of substantially trapezoidal sheet metal members extending toward the central axis of the circular configuration; and (2) forming each of the plurality of substantially trapezoidal sheet metal members into a retention members having a planar leg portion and a planar hook portion, the planar leg portion extending from an inner perimeter of an planar annulus created from the circular configuration, the planar hook portion projecting from the planar leg portion toward the central axis of the circular configuration, the planar hook portion being acute to the central axis.